采煤塌陷地土壤重金属空间分布及潜在风险评价

Spatial Distribution and Potential Ecological Risk Analysis on Soil Heavy Metal in Coal Mine Subsidence Area

为全面了解徐州某采煤塌陷地土壤重金属含量及其潜在生态危害程度,在研究区内共采集了12个土壤样品,测试了Mn,Cu,Ni,Fe,Cd,Zn共6种重金属元素的含量,并采用单因子指数法对土壤重金属污染进行了分析和评价。结果表明,徐州某采煤塌陷地土壤环境总体污染程度处于轻度污染,潜在生态危害处于中等危害程度,属于D级,相对而言,各种重金属污染程度由强至弱依次为:Mn>Fe>Zn>Cd>Cu>Ni,各种重金属污染的潜在生态危害由强至弱依次为:Cd>Mn>Cu>Ni>Fe>Zn,其中,Cd的影响占绝对主导地位。徐州某采煤塌陷地区域土壤重金属潜在生态危害中等,周边耕地区域次之。徐州某采煤塌陷地土壤中6种重金属的超标部分主要来自矿井水排放。

The investigative work was carried out on studying the contents and the potential ecological impact of soil heavy metals in coal mine subsidence area of Xuzhou, Jiangsu province.In the research, 12 soil samples were collected from the research area for testing the contents of 6heavy metals, i.e. Mn, Cu, Ni, Fe, Cd, Zn and subsequently conducted an evaluation on the heavy metal contamination through single factor index method. Statistics indicated that the contamination of overall coal mine subsidence lands in Xuzhou was light and potential ecological risk was moderate, i.e. D level. The order of pollution degree among these metals was Mn>Fe>Zn>Cd>Cu>Ni and the order of potential ecological risk was Cd >Mn >Cu >Ni >Fe >Zn, which means Cd has a significant impact on the environment. In general, the potential ecological risk level of coal mine subsidence lands in Xuzhou was middle, which was little higher than surrounding farmland and the pollution of the 6 heavy metal mainly derived from mine water discharge.